<!DOCTYPE html>
<html>

<head>
    <!-- 背景测试 -->
    <meta charset="utf-8">
    <title>背景测试</title>


    <style>
        input::-webkit-input-placeholder{
            color:red;
        }
        input::-moz-placeholder{   /* Mozilla Firefox 19+ */
            color:red;
        }
        input:-moz-placeholder{    /* Mozilla Firefox 4 to 18 */
            color:red;
        }
        input:-ms-input-placeholder{  /* Internet Explorer 10-11 */
            color:red;
        }
    </style>

</head>

<body>
    <input placeholder="请输入"></input>

</body>

</html>